Heat-conserving air-heating furnace with flue cleaner



July 6, 1948. F. H. ELLIOTT 2,444,499

HEAT CONSERVING AIR HEATING FURNACE WITH FLUE CLEANER Filed Nov. 20, 1943 4 Sheets-Sheet l H- ELLIOTT July 6, 1948.

Filed Nov. 20, 1943 F. H. ELLIOTT 2,444,499 HEAT CONSERVING AIR HEATING FURNACE WITH FLUE CLEANER 4 Sheets?Sheet 2 F. H- ELLIOTT W OWIW y 1948- F. H. ELLIOTT 2,444,499

HEAT CONSERVING AIR HEATING FURNACE WITH FLUE CLEANER Filed NOV. 20, 1943 4 Sheets-Sheet 3 awe/whom E H- ELLIOTT July 6, 1948. F. H. ELLIOTT 2,444,499

HEAT CONSERVING' AIR HEATING FURNACE WITH FLUE CLEANER Filed Nov. 20, 1943 4 Sheets-Sheet 4 F: H- EL LIOTT Patented Jul c, 1948 OFFICE HEAT-CONSERVING AIR-HEATING FUR- NAGE WITH FLUE CLEANER Fred H. Elliott, Big Rapids, Mich.

Application November 20, 1943, Serial No. 511,147

2 Claims. I

This invention relates to a cold smoke furnace having means whereby all heat units will be extracted from the fuel consumed and transferred to air in order to heat the same, in the hot air heating of a room or building, or the like.

It is particularly aimed to provide such a furnace or unit adapted for the burning of either coal or gas and one which employs hollow grate means through which air under pressure is sup- Dlied.

Another object is to provide the furnace with a coal hopper which may be detached from the furnace proper and such a unit as employs coal screws beneath the grate for operation to force or raise the coal between the grates in small furnaces.

vStill further, it is an object to provide a cooling chamber between the outer and inner walls of the combustion chamber and a construction whereby forced air passes through the cooling chamber and then into the grate; a structure having a novel ash pit at the bottom and with a novel heatabsorbing chamber at the top, the wall of which chamber is provided with heat-absorbing fins on the inside and heat-radiating fins on the outside, serving to extend the effective surfaces ofthe wall; a furnace having smoke discharge at the coolest and outermost parts, a furnace wherein the forced cold air passes over and around the outer heat-radiating part of the main heat-absorbing chamber providing a direct means whereby hot air for heating purposes passes from the hottest internal part of the furnace, a structure wherein the cold air entering the furnace to be discharged as hot air, has a continuous flow and is reduced in volume only when coal feeding is stopped, thereby providing means for a cold smoke discharge, and to provide a hot air furnace having a heat producing unit provided with air grates, using gas or coal or a mixture with a forced volume of air for the benefit of its free oxygen, under automatic control, and avoiding the use of a pilot light.

The more specific objects and advantages will become apparent from a consideration of the de-,- scription following taken in connection with accompanying drawings illustrating an operative embodiment.

In said drawings:

Figure 1 is an end elevation of the furnace;

Figure 2 is an elevation of the reverse end of the furnace;

Figure 3 is a side elevation of the furnace;

Figure 4 is a substantially central vertical section taken on the plane of line 4-4 of Figure 5;

Figure 5 is a vertical sectional view taken on the plane of line 5-5 of Figure 1;

Figure 6 is a detail section taken on the line 6-6 of Figure 5;

Figure 7 is a detail vertical sectional view of the upper part of the furnace showing the disposition of the flue-cleaning brush;

Figure 8 is an enlarged elevation detailing the heat-absorbing fins; and

Figure 9 is a fragmentary view also detailing one of said fins at a right angle of Figure 8.

Referring specifically to the drawings wherein like reference characters designate like or similar parts, the furnace may be made any desired size or dimensions, and comprises a suitable casing generally designated [0 and which includes a base ll upon which the furnace is adapted to rest. In one wall of the casing lll'an opening is provided around which a cast iron frame I2 is movabiy secured inorder to give access to the ash pit or chamber l3, and which frame is provided with or mounts a conventional cast iron door it.

Within the combustion chamber of the furnace suggested at I5 is a suitable burner assembly generally designated l6, and which is preferably removable and replaceable. The assembly may consist of a suitably shaped pot or firebox open at the top but having a bottom or base wall I! with a peripheral wall 18 rising therefrom, which is hollow and has inner and outer portions l 9 and 20. Detachable and replaceable grate sections 2| are angularly arranged at the inner portions I9 of wall l8 and coacts with grates or bars 22 spaced therefrom and from each other, all of the grate sections 2| and 22 being in communication with the hollow or space 23 within th wall I B and being provided with discharge orifices at 24.

Air under pressure is suppliedthrough a conduit 25 to the space 23 and discharged through the orifices 24 at the fuel bed. This fire pot or grate may burn coal as hereinafter described and may also selectively burn gaseous fuel, the air forced in or supplied coacting with either the coal or gas, whichever is used.

Said conduit 25 communicates with a blower or fan structure 26 having an intake at 21 so that a fan within the blower 26 will draw the air into the same and then discharge through the conduit 25 to the hollow wall 23. The fan may be operated in any suitable manner, the same having a shaft at 28 equipped with a pulley 29 around which a belt 30 is trained, and which is also trained over a pulley 3| of an electric motor 32,

which operates the same, such motor being adjustably supported on the exterior of the casing by a shelf, bracket or the like 33.

When gas is used as the fuel, it passes from any suitable source through a pipe or conduit 34 under control of an automatic regulator mechanism 35 and then into and through the pipe 36 into the duct 25 for admixture with the air and supplied therewith to the chamber 23. Electric current from any suitable source is provided through conductor means 31 also under control of the automatic regulator mechanism 35 from which conductor means 38 passes to the motor 32 in order to operate the same.

When coal is used as the fuel, it may be supplied through a hopper 39 having a suitable lid or cover at 48. Such hopper 39 has a portion 4| which removably telescopes into an inclined chute 42, forming part of and extending from the fire pot or box l6, through an adjacent wall of the casing l8. When gas is used as a fuel, the hopper 39 may be detached and the chute 42 covered by a conventional closure. Coal entering the hopper through the chute 42, will be elevated by the rotation of a series of screws 43, and passed upwardly between the grate bars 2! and 22 to the predetermined level. These elevating screws 43 have shafts 44 journaled in the bottom wall I! of the hopper or fire box l6 and at their lower ends have double gear wheels 45 keyed thereto and enmeshed with double gear wheels 45 fixed on a shaft 41, journaled in bearings 48, suspended from the bottom wall l1. Said gears 45 and 46 and associated parts are preferably enclosed by a housing 49 to protect them against dust and the like.

One of the gears 49 has rigid with it a bevel gear 58 enmeshed with another bevel gear carried by a laterally extending shaft 52 project ing to the exterior of the casing and journaled, for instance, in the housing 49 and a bearing 53 on the exterior of such casing. Shaft 52 is driven at the desired speed so that the screws 42 will effectively elevate the supplied coal. To this end, a pulley 54 is keyed to the shaft'52, and a belt 55 traverses the same, and a pulley 58 on the driving shaft of an electric motor 51 energized from the same source as the other electrical parts of the apparatus, through conductor 58. Said motor 51 may be supported on the exterior of the casing ID at any appropriate location by means of an adjustable shelf or bracket 59.

Said combustion chamber l5 at the sides is bounded by inner walls 68 spaced from the adjacent side walls of the casing and fastened in place in any suitable manner, preferably being castings and made in sections to facilitate ready removal and replacement. Such walls 88 support the dome or wall 6! for the combustion chamber, which is preferably made as a single casting, has ribs 62 at the sides thereof, providing flanges which are bolted or are otherwise fastened at 63 to the casing ID. The dome 8! includes a duct 64 extending through the easing 18 and terminating in a flange or frame 65, closed by a conventional inspection or access door 88,

Particular attention is called to the fact that the, inner surface of the dome 6| has any desired number of fins or projections on the interior thereof and any desired number of fins or prolections on the exterior thereof. Such fins 61 and 88 serve to increase the effective area or' surface of the dome or wall 8| and the fins 81 function to absorb heat while the fins 68 function to radiate heat.

Atmospheric air is blown into the casing I8 at the top through a suitable duct 89 and connections, by means of an encased fan 18 mounted on the casing, and which fan may be driven by a belt ll, trained over a pulley 12 on its main shaft, and also trained over a pulley l3, trained over the drive shaft of an electric motor 14, adapted to be energized from the same source as all the other electrical parts of the apparatus, by conductors 15. It will be understood that all of the operating parts are under suitable switch control and regulation. Motor 14 is adjustably mounted or supported as by means of a bracket 16 fastened to the exterior of the casing l8. Such atmospheric or cold air entering the casing at the top through the duct 89 travels downwardly directed by staggered bafiies or air dividers ll fastened to and extending from opposite side walls of the casing l8 and such air travels over and is heated by the dome and adjacent parts, including the fins 68 and thereafter discharges through a suitable hot air outlet means 18 mounted on the casing and having outlet openings 19, which are uncovered or under damper control or otherwise as preferred.

The smoke or product of combustion from the chamber is will discharge through a tortuous conduit or flue generally designated 88, the same having a vertical leg 8| open at the bottom and connected to the casting of the dome 6|, and also having a lateral branch 92 opening through the dome at 83 and connected to the dome adjacent the same. A heat-retainer wall 84 is provided adjacent the opening 83, causing th product to escape over its top, then downwardly and into the opening 83.

Said flue 88 is preferably single casting and includes U-shaped portions 85 of any desired number and at the ends of which, they are preferably enlarged in any suitable manner as at 88 to facilitate fastening within the casing by means of bolts or the equivalent 81.

Said discharge flue at the upper portion thereof, has a box or enlargement 88 integral with it, and disposed exteriorly of the casing, with a flange 89 secured to the interior of the casing. Said box at the top has a collar 89 serving as a smoke outlet. From the box 88, a pipe 98 of any suitable form, preferably made in sections detachably connected together and to the box and to the casing, leads and communicates with the interior of the casing in line with the ash pit or chamber. This pipe functions for the delivery of soot from the upper portion of the discharge flue to the ash pit. And, from Figure 1 in particular, it will be noted that the upper portion of the pipe or conduit 98 is preferably flared as at 9|.

A suitable transversely disposed brush 92 which may normally be maintained in the box or enlargement 88, is adapted to be moved throughout the length of the tortuous duct 88 and then back in the reverse direction. To this end, a pair of laterally spaced apart flexible chains or the equivalent 93 are attached at one end to the brush 92 and pass throughout the tortuous discharge flue 88 and then through the housing or guide 94 detachably and replaceably connected to the housing 88 and to the casing l 8 about suitable openings in both for passage and operation of the chains. It will be understood that the chains 93 are connected to opposite sides of the brush 92 so that when the chains are moved, the brush 92 will follow the movement of the chains and dislodge soot from the discharge flue, caus- 9 ing it to fall through the vertical ledge 81 or the soot pipe 90 into the ash pit.

It will be noted that the housing 96 includes detachable sections 95 at their lower end, which are mounted on th casing and in turn mount sprocket wheels 96 in any suitable manner by means of a shaft 91 journaled in suitable bearings 99 appropriately mounted on the walls of the housing. It will be understood that the chains 83 are trained over the sprocket wheels 96. A crank 99 is permanently or removably attached to one end of the shaft 91 and located exteriorly of the casing l0, whereby it may be manually operated as desired to remove the chains 93 and accordingly the brush 92 to dislodge soot for more efllcient operation.

I preferably provide a clean-out chute I as an integral part of the flre box or pot I6, the

same communicating with the base thereof and of the firebox, said flue line and shell having an,

air chamber therebetween whereby air is heated by the hot products of combustion passing through said flue line, an elongated flexible element trained through the flue line, a conduit extending from the upper end of the flue line downwardly to a point below the lower end of the flue line and opening into the interior of the shell, said flexible element being endless and-also trained through said conduit, means for imparting a longitudinal motion to said flexible element, and a flue cleaning brush connected to the flexible element said shell having openings at its upper and lower portions through which the flexible element is trained.

2. In a furnace structure comprising a shell having a firebox in the lower portion thereof, a; serpentine shaped flue extending upwardly from adjacent the firebox, an outlet at the top of the shell for said flue, said serpentine shaped flue line extending back and forth above the region of the firebox, said flue line and the shell having an air chamber therebetween whereby air is heated by the hot products of combustion passing through said flue line, an elongated flexible element trained through the flue line, a conduit extending from the upper end of the flue line downwardly to a point below the lower end of the flue line and opening into the interior of the shell, said flexible element being endless and also trained through said conduit, means for imparting longitudinal motion to said flexible element, and a flue cleaning brush connected to the flexible element said shell having openings at its upper and lower portions through which the flexible element is trained, said flue being provided with an enlarged chamber at its upper end and underlying the outlet, an ash pit underlying the firebox, and a chute extending downwardly from the enlarged chamber to a point opening into the interior of the shell below the lower end of the flue line to permit the descent of soot from the enlarged chamber to the ash pit.

FRED H. ELLIOTT.

REFERENCES CITED The following references are of record in the file of this patent: v

UNITED STATES PATENTS Number Name Date 54,795 Wallace May 15, 1866 64,540 Kafer et al May 7, 1867 120,257 Finch Oct. 24, 1871 420,636 Switzer Feb. 4, 1890 659,471 Feeney Oct. 9, 1900 751,136 Anthony Feb. 2, 1904 751,530 May Feb.'9, 1904 1,202,012 Adams Oct. 24, 1916 1,658,367 Bollinger Feb. 7, 1928 1,717,715 Lush June 18, 1929 1,733,561 Sherwood Oct. 29, 1929 1,841,210 Russell Jan. 12, 1932 1,857,354 Chapman May 10, 1932 1,888,586 Chapman Nov. 22, 1932 1,941,822 Bard Jan. 2, 1934 2,072,874 Geiselman Mar. 9, 1937 2,160,509 Lindsay May 30, 1939 2,286,665 Blair June 16, 1942 

